1. Field of the Invention
The present invention relates generally to a cable connector for connecting an electrical signal cable to an electrical signal port. More particularly, the present invention relates in one embodiment to a “cinch” or gripping-type cable connector which plugs into a signal port in a manner such that the connector is very secure, but easily unplugged.
2. Description of Related Art
A “cinch” or gripping connector, also referred to as an “RCA connector” or a “phono connector,” is a type of electrical connector that is commonly used in the transmission of audio and/or video signals. In use, the connector is connected or “plugged into” a corresponding port that is often referred to as an “RCA jack” or port. The end of the connector opposite to the jack is connected to an electrical signal cable.
Some types of electrical signal ports, such as RF ports, are comprised of a cylindrical body which protrudes from a signal receiving and/or transmitting device, and which has threads on the cylindrical outer wall of the body. The corresponding connector to be fitted to such a port includes a nut which can be threaded onto the port to secure the connector to the port. While such an arrangement provides a highly secure connection with low signal loss, it is not satisfactory when there is a need to quickly connect or disconnect the cable from the device, or when the cable needs to be repeatedly connected to and disconnected from the device.
In such circumstances, an RCA port and RCA connector may be used to enable simple and quick connections and disconnections of the cable to the device. The RCA connector is comprised of an electrically conductive central pin or male connector surrounded by an electrically conductive ring. The pin and ring are insulated from each other. The pin is connected to an electrical signal conductor contained within the signal cable that is connected at the opposite end of the connector. In a typical coaxial cable, such as 75 ohm RF cable, the central conductor of the cable may extend directly into the conductive central pin. The ring of the connector is connected to the outer shielding of the cable.
The RCA port or jack is comprised of the aforementioned cylindrical body with a central hole. The exterior of the cylindrical body is comprised of a conductive sleeve that is typically connected to a ground. The central hole has a conductor contained therein, which is separated from the outer conductive sleeve by a suitable insulator, such as plastic or ceramic. When the connector and the port are connected to each other, the central pin of the connector is received in the central hole of the port, and an electrical connection is made between the central pin and the conductor within the central hole. In addition to providing an electrical connection, the engagement of the central pin with the hole serves, to some extent, to mechanically join the connector to the port by friction between them.
However, the main mechanical connecting force between the RCA connector and the port is provided by the engagement of the outer ring of the connector with the outer sleeve of the port. Typically, the sleeve of the port is slightly smaller in diameter and longer than the ring on the connector, such that the ring of the connector may fit over the sleeve of the port. The ring of the connector may be segmented into fingers, and sized such that an interference fit occurs between the connector ring and port sleeve, with the fingers of the connector ring bending radially outwardly when the connector is fitted to the port. The ring of the connector is dimensioned and configured so as to provide a gripping action onto the outer sleeve of the port.
This connection between the RCA connector and the port is often not sufficient to provide a reliable connection with good signal transmission through the connector and port. The sizes of RCA ports may vary, such that the ring of the connector may not have a snug fit with a particular port. Additionally, the fingers of the connector may become fatigued and/or bent with repeated connection and disconnection, such that they no longer provide sufficient clamping force on the sleeve of the port to maintain the connection and/or provide sufficient grounding continuity between the connector and the port.
What is needed is an RCA or gripping connector that can be quickly connected to and disconnected from a corresponding port, while having a strong mechanical engagement with the port and reliable electrical continuity through the port when connected. It is desirable for the connector to have the strength and reliability of a threaded connection, but without the use of a threaded fastener which requires many rotations to secure it on the port, and which may require a tool such as a wrench, to perform a final tightening of the fastener.
There is a further need for a single gripping connector that can accommodate a range of port sizes, such that it is connectable and therefore reverse-compatible with a variety of existing audio-visual products that have been sold and are currently in use.